Nonlinear dynamic analysis of gear system in shearer cutting section under wear failure

2021 ◽  
pp. 146441932110535
Author(s):  
Lianchao Sheng ◽  
Wei Li ◽  
Guo Ye ◽  
Ke Feng
Keyword(s):  
Nonlinear Dynamic Analysis ◽  
Transmission Error ◽  
Gear System ◽  
Radial Clearance ◽  
Gear Teeth ◽  
Meshing Stiffness ◽  
Vibration Impact ◽  
Coupling Factors ◽  
Dynamic Meshing ◽  
Internal Error

Gear wear failure is one of the important failures of the gear system in the shearer cutting section. To reveal the influence mechanism of shearer cutting gear wear on the system dynamic characteristics, considering coupling factors such as time-varying meshing stiffness, dynamic gear clearance, internal error excitation, end load constraint and bearing radial clearance under wear failure, an improved dynamic model of shearer drive gear system is introduced to present an in-depth investigation of uniform wear of gear teeth effect. The dynamic meshing stiffness of gears under different degrees of wear is analysed. Furthermore, the bifurcation diagram is utilized to observe the motion state of the system experiencing different excitation frequencies, support damping as well as terminal loads. It is demonstrated that the gear surface wear could bring a change in gear dynamic transmission error, vibration impact state and amplitude, which is mainly manifested in increasing the unstable area and the vibration amplitude of the gear system, providing a method for monitoring and diagnosing of gear surface faults.

Nonlinear Dynamic Analysis of a New Antibacklash Gear Mechanism Design for Reducing Dynamic Transmission Error

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
S. R. Besharati ◽  
V. Dabbagh ◽  
H. Amini ◽  
Ahmed A. D. Sarhan ◽  
J. Akbari ◽  
...  
Keyword(s):  
Mechanism Design ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Transmission Error ◽  
Mesh Stiffness ◽  
Gear Teeth ◽  
Dynamic Transmission Error ◽  
Gear Mechanism ◽  
Lower Transmission ◽  
Input Torque

In this study, a new antibacklash gear mechanism design comprising three pinions and a rack is introduced. This mechanism offers several advantages compared to conventional antibacklash mechanisms, such as lower transmission error as well as lower required preload. Nonlinear dynamic modeling of this mechanism is developed to acquire insight into its dynamic behavior. It is observed that the amount of preload required to diminish the backlash depends on the applied input torque and nature of periodic mesh stiffness. Then, an attempt is made to obtain an approximate relation to find the minimum requiring preload to preserve the system’s antibacklash property and reduce friction and wear on the gear teeth. The mesh stiffness of the mated gears, rack, and pinion is achieved via finite element method. Assuming that all teeth are rigid and static transmission error is negligible, dynamic transmission error (DTE) would be zero for every input torque, which is a unique trait, not yet proposed in previous research.

Fault Detection of Gears With Different Root Crack Size Using Wavelet

2015 ◽  
Author(s):  
Xinpeng Hu ◽  
Xi Wu ◽  
Jixin Wang ◽  
Jim Meagher
Keyword(s):  
Vibration Signal ◽  
Crack Size ◽  
Gear System ◽  
Time Varying ◽  
Hertz Contact ◽  
Transient Vibration ◽  
Gear Teeth ◽  
Meshing Stiffness ◽  
Vibration Signatures ◽  
Root Crack

Although tremendous effort has been applied to develop reliable strategies for detecting tooth cracks of gearboxes, these methods have generally fallen short of the required performance. Cracks are usually initiated at the root of a tooth and are very difficult to be identified from time-domain measurement. The vibration signal transformed by wavelet is sensitive to energy change. In this study, the transient vibration variations induced by different sizes of cracks at the tooth root are captured using wavelet. Firstly, as the main parametric excitation, the time-varying gear meshing stiffness caused by the alternating of engaged gear teeth is accurately calculated based on energy method, in which comprehensive deformations including Hertz contact, axial compression, bending, shearing and fillet-foundation deflection are taken into consideration. Moreover, a sophisticated dynamic theoretical model is used to simulate a practical gear system. Unique vibration signatures are captured through the comparison of cracked and perfect gear system.

Analysis of Gear Noise and Dynamic Transmission Error Measurements

2004 ◽  
Author(s):  
Mats Henriksson
Keyword(s):  
Dynamic Properties ◽  
Transmission Error ◽  
Gear System ◽  
Gear Pair ◽  
Gear Noise ◽  
Gear Teeth ◽  
Opposite Trend ◽  
Dynamic Transmission Error

Measurements of dynamic transmission error (DTE) and noise have been performed on a truck gearbox. The DTE is related to the dynamic properties of the complete gear system. To investigate the coupling between noise and DTE, the correlation between noise and DTE is calculated for fixed speeds, as the torque is increased. The highest correlation is found for the low split gear pair, which is located closest to the gearbox housing. When the correlation is low, one of the reasons can be a resonance of the shafts, although not all resonances effect the correlation between noise and DTE. The DTE is also compared to calculated static TE for the gear teeth. Both the DTE and noise for the fifth gear increases as the torque is increased. The calculated static TE shows the opposite trend and decreases as the torque is increased.

Bending-torsional-axial-pendular nonlinear dynamic modeling and frequency response analysis of a marine double-helical gear drive system considering backlash

2021 ◽  
pp. 146134842110657
Author(s):  
Hao Dong ◽  
Yue Bi ◽  
bo Wen ◽  
Zhen-bin Liu ◽  
Li-bang Wang
Keyword(s):  
Frequency Response ◽  
Dynamic Modeling ◽  
External Load ◽  
Transmission Error ◽  
Helical Gear ◽  
Gear System ◽  
Time Varying ◽  
Vibration Displacement ◽  
Meshing Stiffness ◽  
Nonlinear Dynamic Modeling

The double-helical gear system was widely used in ship transmission. In order to study the influence of backlash on the nonlinear frequency response characteristics of marine double-helical gear system, according to the structural characteristics of double-helical gear transmission, considering the time-varying meshing stiffness, backlash, damping, comprehensive transmission error, external load excitation, and other factors, a three-dimensional bending-torsional-axial-pendular coupling nonlinear dynamic modeling and dynamic differential equation of 24-DOF double-helical gear transmission system were established. The Runge–Kutta numerical method was used to analyze the influence of backlash, time-varying meshing stiffness, damping, error and external load excitation on the amplitude frequency characteristics. The results show that the backlash can cause the runout of the double-helical gear system, and the system has first harmonic and second harmonic response. With the increase of backlash, the amplitude of the system increases and the jumping phenomenon remains unchanged. The amplitude frequency response of the system is stimulated by time-varying meshing stiffness and comprehensive transmission error, and restrained by damping and external load excitation. The vibration displacement amplitude of the system increases with the increase of vibration displacement and has little effect on the state change of the system. The vibration test of double-helical gear is carried out. The frequency response components obtained by numerical simulation are basically consistent with the experimental results, which proves the correctness of the theoretical calculation. It provides a technical basis for the study of vibration and noise reduction performance of double-helical gear.

Study on the Dynamic Excitation of the Star Gearing

2011 ◽  
Vol 86 ◽  
pp. 116-119
Author(s):  
Li Dong Jiang ◽  
Bao Xing Liu ◽  
Zhen Rong Zhu ◽  
Ying Li Chen
Keyword(s):  
Dynamic Response ◽  
Coupled Model ◽  
Transmission Error ◽  
Response Analysis ◽  
Dynamic Force ◽  
Dynamic Response Analysis ◽  
Meshing Stiffness ◽  
Dynamic Excitation ◽  
Dynamic Meshing

Study on the dynamic excitation is the basis of dynamic response analysis of gearbox. In the paper, the dynamic coupled model of the star gearing was established. By analyzing the casing substructure and extracting the coherency nodes, the gearing and casing was coupled. On the basis of analyzing dynamic meshing stiffness and transmission error, the dynamic meshing force of the star gearing was analyzed and calculated. By converting the dynamic meshing force, the dynamic force on the bearing was obtained. The dynamic excitation for dynamic response analysis of casing was achieved by applying the load on the coherency nodes. The method used in the paper has provided proper dynamic excitation for the dynamic response analysis of casing.

Effects of the Gear Tooth Modification on the Nonlinear Dynamics of Gear Transmission System

2010 ◽  
Vol 97-101 ◽  
pp. 2764-2769
Author(s):  
Si Yu Chen ◽  
Jin Yuan Tang ◽  
C.W. Luo
Keyword(s):  
Nonlinear Dynamics ◽  
Gear Tooth ◽  
Simulation Method ◽  
Transmission Error ◽  
Dynamic Responses ◽  
Meshing Stiffness ◽  
Gear Transmission System ◽  
Tooth Modification ◽  
Static Transmission Error ◽  
Misalignment Error

The effects of tooth modification on the nonlinear dynamic behaviors are studied in this paper. Firstly, the static transmission error under load combined with misalignment error and modification are deduced. These effects can be introduced directly in the meshing stiffness and static transmission error models. Then the effect of two different type of tooth modification combined with misalignment error on the dynamic responses are investigated by using numerical simulation method. The numerical results show that the misalignment error has a significant effect on the static transmission error. The tooth crowning modification is generally preferred for absorbing the misalignment error by comparing with the tip and root relief. The tip and root relief can not resolve the vibration problem induced by misalignment error but the crowning modification can reduce the vibration significantly.

Research on dynamic characteristics of gear system considering the influence of temperature on material performance

2021 ◽  
pp. 107754632110026
Author(s):  
Zhou Sun ◽  
Siyu Chen ◽  
Xuan Tao ◽  
Zehua Hu
Keyword(s):  
Elastic Modulus ◽  
Dynamic Characteristics ◽  
Poisson’S Ratio ◽  
Gear System ◽  
Poisson's Ratio ◽  
Effect Of Temperature ◽  
Time Varying ◽  
Influence Of Temperature ◽  
Meshing Stiffness ◽  
Influence Of Temperature On

Under high-speed and heavy-load conditions, the influence of temperature on the gear system is extremely important. Basically, the current work on the effect of temperature mostly considers the flash temperature or the overall temperature field to cause expansion at the meshing point and then affects nonlinear factors such as time-varying meshing stiffness, which lead to the deterioration of the dynamic transmission. This work considers the effect of temperature on the material’s elastic modulus and Poisson’s ratio and relates the temperature to the time-varying meshing stiffness. The effects of temperature on the elastic modulus and Poisson’s ratio are expressed as functions and brought into the improved energy method stiffness calculation formula. Then, the dynamic characteristics of the gear system are analyzed. With the bifurcation diagram, phase, Poincaré, and fast Fourier transform plots of the gear system, the influence of temperature on the nonlinear dynamics of the gear system is discussed. The numerical analysis results show that as the temperature increases, the dynamic response of the system in the middle-speed region gradually changes from periodic motion to chaos.

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